- Implemented a hack to improve the UFF-generated geometries of 3- and
  4-membered rings containing sp2 atoms. The hack consists in
  altering on-the-fly the theta0 equilibrium angle, depending on
  ring size and collocation of the two edges of the angle (i.e.,
  both edges inside the ring or one inside and one outside)
- Added a relevant test in
  Code/GraphMol/ForceFieldHelpers/UFF/testUFFHelpers.cpp